Mr Downer said: "The elephants were remarkably stable - almost like a steady-cam, and they only needed a little bit of training to carry and set down the cameras.

"With these cameras, anywhere a tiger went or whatever it did, we could keep on filming it. They were the ultimate filming devices."

Mr Downer added: "This sort of thing hasn't been done before.

"It is a bit of a bonkers idea, and in my wildest dreams, when I thought about the challenges of filming tigers, I never thought we would suceed in doing what we did in this way, but now it seems the most natural thing in the world."

The cameras also recorded other animals, including langur monkeys, sloth bears and red dogs.